Process for making decolorizing carbon from peat



Patented Sept. 3%, i924.

Q3211? WOOD LEADBEATER,

OF DONCASTER, ENGLAND.

No Drawing. Application filed May 12,

i To all whom it may concern Be it known that 1, JOHN Wool) LEAD- BEATER, residing at Doncastcr. in the county of York, England, have invented new and useful Improvements in Processes forMaking Decolorizing Carbon from Peat, of which the following is a specification.

This invention relates to improvements in the means and method of obtaining carbon from peat,in closed chambers,for decolorizing purposes, such as, for example,

say, for decolorizing sugar solutions, or edible, or vegetable, or mineral, or other oils, or paraffin wax and the like, and in apparatus for drying and carbonizing peat.

In this invention a dry mixture of dried peat alone and good ground caustic lime (unslacked ground lime) is employed. The lime being added to the peat helps to break up and disintegrate the fibres of the peat and a charcoal of low density and specific gravity is produced in a granular friable state due to the use of a dry mixture for distillation. The production of carbon by this process does not require grinding before further treatment and the production of volatile distillation products (oils, acetic acid, methyl alcohol, andthe like) are in slight excess of the amount obtained by the distillation of peat alone.

According to this invention the peat is obtained in the usual and ordinary manner, and in its natural state contains more or less moisture. The percentage of the moisture varies according to the nature of the bog from which it is obtained. Before treating it for obtaining a decolorizing carbon from peat according to this invention the peat requires to be either air-dried in the usual manner, or dried in a furnace or retort, such as, say, an ordinary D-shaped coal gas retort, or any other suitable retort or oven, capable of beingfixed in a framework, may be employed and heated to a suitable temperature depending on the moisture in the peat tobe carbonized, or any other convenient mechanical means may be employed for drying purposes.

If the peat be dried in retorts orin a furnace the moisture should not be reduced beyond the percentage present in air-dried eat P When the peat contains say from twentyfive to forty per cent of moisture, then a suitable temperature increasing from about five hundred and fifty to two thousand de- 1919. Serial No. 296,665.

.grees Fahrenheit could be employed, but I would distinctly have it understood that the just named percentage and degrees, as well as any other. percentages, degrees, or weights, may be varied or altered as cir cumstances' require.

For drying the peat, other than by air, a furnace or oven or a retort, having trays therein for preventing the waste ofjthe material operated upon, is provided with one or more exits for the gas and other products accumulating therein, and the said gas or products are conducted to a holder or other receptacle by a pipe, or pipes provided with one or more valves or stop cocks. The retort is made of metal or fireclay, or other suitable or refractory material and it is open at one or both of its ends, which end or ends is or are subsequently covered by one or two detachable doors made gas-tight by any convenient means, and retained in position by the bridge piece and screw, or by any other suitable means, such as are used in gas works for closing and .sealin the ends of the retorts. If desired, thoug not necessarily so, a retort open at both ends may have, in the case of very long retorts, a transverse division piece at or about its centre.

The peat to be treated can be laced in an ordinary retort oroven for rying purposes, but preferablyin the/trays or receptacles, and after it has been ground it is necessary at the later stage to place it in trays or receptacles instead of being placed directly into the retort, soas to avoid the waste that would otherwise occur.

The peat after being dried is ground or crushed or finely divided for reducing it to a granular state or form and it is then laid in layers to form abed. The layers of ground or crushed dried peat are each thoroughly mixed with a percentage of goodv ground caustic lime-,-unslacked or quick lime,-say, in the proportion of, about, five pounds avoirdupois of lime to each one hundredweight of dried ground peat. The

for example, increasing from five hundred and fifty to two thousand degrees Fahrenheit,the carbonization'is effected or aided by the action of the lime by disintegrating the fibrous matters in the peat and there is a slightly increased yield of tar. Such carbonization is effected without access of air to the material in the retort. The resultant tar by-products are recoveredby any ordinary means and in the same manner as in coal gas manufacture, and the lime emwith the acid solution and before beingployed also slightl increases the yield of the by-products. mm the resultant tar various light or heavy oils, acetic acid, methyl alcohol, and the like may be distilled in the ordinary way.

After the above described process of carbonization has taken place the resultant residue will be in the form of powdered or granular charcoal or carbon and therefore no grinding is required. The said resultant residue contains more or less percentage of ash or foreign and deleterious substances which vary according to the locality or source from which the peat is obtained.

Some of the carbons made from peat have varying quantities of ash or foreign substances or impurities such as alumina or silica, or sand. For the purpose of removing such impurities the carbon (obtained as above described from peat) is treated with hydrochloric acid, or sulphuric acid, or hydrofluoric acid, or any other acid or combination of acids- The quantities of such acids, or combination of acids, vary according to the quantities of the impurities,- found by analysis,-that would interfere with or retard the decolorizing effect of the peat carbon.

When the quantity and nature of the impurities have been ascertained,by analysis,the residue from the just named carbonization is placed in a suitable-lead lined vessel and boiled inwater to which is added and mixed,say, for example,--hydrochloric, or sulphuric, or hydrofluoric acid of the ordinary commercial strength, or such other acid or acids as are or may be found requisite to treat and remove the ash or foreign substances and im urities from the peat charcoal or carbon. f the ash or foreign: substances or impurities amount to, say, about ten to fifteen per cent of the resultant residue then it is first treated with about, say, a two per cent solution of hydrochloric or other acid. If after the boiling with the just named solution of hydrochloric acid there is still found,-by analysis,-any ash or foreign substances or impurities, such as alumina, or silica,'or sand, remainlng in the resultant residue it may be found neces sary to treat it with one or more other acids, which will vary according to the nature of .the ash or foreign substances or impurities remaining in the residue.

the resultant residue to the required degree of moisture.

After the residual carbon has been treated earth, or hydrated silicate of aluminium, or

kieselguhr, or diatomite, or other infusorial earth containing nearly pure silica.

Owing to the finely divided state of the decolorizing carbon obtained from peat by the said process, the particles of carbon are very liable to be carried through the filter and to pass into the syrup or oil being treated, thereby causing or producing a cloudiness in the latter. The addition of fullers earth not only prevents this, but at the same 4 time a better and more eificlent decolourizer is obtained.

The material is then a second time placed in the above named retort or oven and heated or dried therein.

In practice it has been found difiicult to get a single decolorizing agent to completely dec-olourize an oil, a certain portion being difficult to remove when a single agent has been used. Further, no single agent is equally elficient with all oils, due to the fact that the nature of the colouring matters in any oil is probably different from the colouring matters in another oil, andithat one. decolorizing agent is more efficient in withdrawing one colour than another. Thus fullers earth seems to have little effect in removing the colouring matters present in sesame oil or ground nut oil while it produces a very marked effect in decolorizing cotton seed oil, so that a mixture of agents,

Each of the said two a ents,1the decolorizing carbon and the fu lers earth,-problemme ablywithdraws a difierent portion of ,the

colouring matters present in the cotton seed 5-the1n are taken singly.

'decolorizing agent produced. according tothis invention is not merelg1 a mixture of the said carbon and the in ers earth in the proportions named, but such a mixture 9 which has afterwards been driedandheated additional efi'ect is obtainedby heating the two ingredients together whereby the decolorizing efieot of the mixture thus treat ed is greater than the efiect of an ordinary v 15 untreated mechanical mixture of. two ingredients.

What I claim is p The herein described, method of preparing al'material for decloriz ing suar solutions, and oil comprisin drying ely divided 'peat, mixing the lied and finely divided peat with finely dividw caustic lime, heating said mixture; to carbonize the peat therein, treating vthe residual carbon with an inorganic acid; to remove ash and foreign substances therefrom, combining the cleaned carbon with an infusorial earth, and. finally heating and dryin the mixed materials.

JOHN W OD LEADBEATER. Witnesses W. FUnN-n'r,

ALICE MARY A 

